Battery life

Hi Elizabeth,

All common battery formulas have reduced output when cold, but some more than others. Lithium cells are the least affected, followed by NiMH and then common alkalines, which are really poor. Additionally, cold temps can affect the device itself, especially cameras with a lot of little motors.

Rechargable batteries lose capacity with age, so that can compound the problem. "Smart" chargers can oftentimes restore a lot of that capacity, but not the charger supplied with the device or the rechargables.

Keeping the battery or gizmo warm always helps. So does shutting off unneeded features, such as picture playback.

Cheers,

Rick

Hi Elizabeth

This is a known problem, with a known solution.

The problem is that most battery chemistry is water-based. But, water freezes around 0 C as you know. Yes, that means that most batteries do freeze just a little below 0 C (32 F). When they freeze, they die – rather quickly too.

However, the Energiser lithium batteries (e2, or 'ultimate') are not water-based and they can keep working down to some quite horrible temperature (-40 C from memory). So that's what we always use in the cold.

Yes, they are non-rechargeable, but they last about 7x longer than an ordinary alkaline battery, and despite their very high up-front cost, they work out cheaper in the long run. Also they are lighter than the other batteries.

I don't know what you have in your camera. The lithium-ion rechargeables should keep working in the cold, but the rest of the camera mechanics (motors etc) can be a serious load in the cold when the lubricants freeze up. It used to be possible to get SLR cameras 'winterised', but these days you would be better advised just to keep the camera inside your jacket.

Cheers

Lots of great food for thought; thanks.

My charger is an old Rayovac, maybe 10 years old. Should I replace it with a "Smart" charger? What will that do? Any specific brand recommendations? (It only needs to recharge AA/AAA batteries; and I don't need a fast/1- or 2-hour charger.)

Do NiMH rechargeable batteries have a shelf life? It may be that I simply have to recycle some of my old ones (from 10 years ago)!

Roger, thanks for the lithium E2 suggestion. I think I'll buy a pair and try them out.

– Elizabeth

Hi Elizabeth,

I use one of these:

http://www.amazon.com/Maha-Powerex-MH-C9000-WizardOne-Charger-Analyzer/dp/B000NLUSLM

It does a good job of resurrecting old cells and also measures actual capacity, which is helpful deciding which to keep and which to retire, as well as pairing batteries with like capacities for best performance. NiMH and Li-ion cells have shelf lives, which is why it's useful to know their actual capacity (not easy with Li-ion unfortunately).

Cheers,

Rick

Everything stated so far is accurate. I would guess that the Rayovac charger is not a smart charger, but it would be otherwise decent. Some smart chargers will sense the charge state of each individual cell that you have plugged into it, and then they will apply more power to the weak ones. Most smart chargers will apply charging power until each cell of the set looks normal, and then the power tapers off. It will continue to apply a tiny pulse of charging power periodically until the cells are removed.

Lithium primary batteries are the lightest and work to the coldest temperatures. They have very high energy density, but they are the most expensive to purchase. Since they have a very long shelf life (10 years), they are good to put into some seldom-used emergency device. I use those when I am on a very long trip where I will not have any commercial AC power for chargers.

Some ordinary appliance like a headlamp that gets used routinely might work best with NiMH for cheap operation. NiMH has some self-discharge, which means that they are OK if you charge them, use them, and repeat the cycle routinely. If you charge them and leave them sitting for a long time, you might get a half-flat battery.

For me, a camera battery is kind of critical, so I don't fool around with cheap batteries.

Just about each different appliance has a different best solution, so you just have to try them out to see what works best for you.

–B.G.–

Elizabeth
Sanyo has upgraded the Eneloop line this year. They work at lower temps and stay charged for longer.
The charger you use does make a big difference. Most charge all of the batteries at the same time so when one cell is charged it stops charging the others. Also to be avoided are the fast chargers . The one that Rick recommends is a very good one.
Lots of good info at the Candelpowerforum, for example :
http://www.candlepowerforums.com/vb/showthread.php?t=212681
Franco